Gadolinium oxide luminophore activated with bismuth - produces visible light when excited by ultraviolet or X=rays, used in fluorescent screens

摘要

The luminophore consists of Gd2O3 which is activated by 0.1-1 atomic % Bi, esp. 0.3 atomic % Bi to obtain Gd2O3:Bi. The pref. luminophore is made using a mixt. of 361-8 g Gd2O3 with 4.66 g Bi2O3, plus 36 g Na2B4O7 used as a flux. This mixt. (1) is milled for 12 hours in a ball mill; heated 1 hour at 1100 degrees C; crushed; and sieved, esp. using a sieve with 35 mu m mesh width. The Na2B4O7 may form 1-20Wt% of the mixt. As compared with other luminophors, only a relatively small amt. of an inexpensive activator, viz. Bi, is required, so the cost of the luminophore is reduced; and bright white light is obtd. when the luminophore is exited by ultraviolet rays.